The association between exposure to a rear-end collision and future health complaints

Different symptoms, together with neck pain, have been attributed to persons with persistent complaints after a previous motor vehicle crash (MVC) and are sometimes referred to as the "late whiplash syndrome." A cohort study was conducted to determine whether exposure to a rear-end collision, with or without whiplash injury, is associated with future health complaints. The results regarding future neck or shoulder pain have previously been described, and the objective of the present report was to focus on outcomes other than neck pain. Included in the study were persons 18 to 65 years of age and covered by traffic insurance at one of the largest insurance companies in Sweden. Claim reports were collected from the period November 1987 to April 1988. Drivers exposed to a rear-end collision were divided into two subgroups: those with reported whiplash injury (n = 232) and those without reported whiplash injury (n = 204). For comparison, 3688 subjects who were unexposed to MVCs were selected, with consideration taken to the age and gender distribution in the exposed subgroups. The prevalence of different health complaints among the study subjects was estimated according to a mailed questionnaire at follow-up in 1994, 7 years after the rear-end collision. When exposed subjects with whiplash injury were compared to unexposed subjects, increased relative risks in the range of 1.6-3.7 were seen for headache, thoracic and low back pain, as well as for fatigue, sleep disturbances and ill health. No corresponding increased risks were found among the exposed subjects without reported whiplash injury. We conclude that rear-end collisions resulting in reported whiplash injuries seem to have a substantial impact on health complaints, even a long time after the collision. There is a need to identify factors that predict a non-favorable outcome in order to improve clinical management.     

Occupant- and crash-related factors associated with the risk of whiplash injury

PURPOSE: Given that a motor vehicle crash (MVC) had occurred, to evaluate whether occupant- and crash-related factors, such as age, gender, seating position and type of MVC are associated with the risk of whiplash injury. METHODS: A study of occupants in cars covered by motor insurance at one of the largest insurance companies in Sweden, was undertaken during a one-year period. The study population comprised all occupants in cars exposed to an MVC in which at least one occupant was injured (n = 7120). Adjusted estimates of the relative risk of whiplash injury, associated with the different factors, were calculated by means of binomial regression analysis. RESULTS: Considering different MVCs, rear-end collisions were associated with the highest relative risk of whiplash injury when compared with side impacts (1.82; 95% CI 1.68-1.96), while drivers showed the strongest association with respect to seating position when compared with passengers in the rear seat (1.78; 95% CI 1.60-1.97). Females had a somewhat higher relative risk of whiplash injury than males (1.20; 95% CI 1.16-1.25). Regarding age, the relative risk was moderately increased across the different age groups when compared with the oldest age group. No interaction was observed on the additive scale. CONCLUSIONS: Given that an MVC had occurred, subjects exposed to a rear-end collision and drivers had a substantial increased risk of whiplash injury, while age and gender were of minor importance.     

Long-term labour-market performance of whiplash claimants

A whiplash is a sudden acceleration–deceleration of the neck and head, typically associated with a rear-end car collision that may produce injuries in the soft tissue. Often there are no objective signs or symptoms of injury, and diagnosing lasting whiplash-associated disorders (WAD) is difficult, in particular for individuals with mild or moderate injuries. This leaves a scope for compensation-seeking behaviour. The medical literature disagrees on the importance of this explanation. In this paper we trace the long-term earnings of a group of Danish individuals with mild to moderate injuries claiming compensation for having permanently lost earnings capacity and investigate if they return to their full pre-whiplash earnings when the insurance claim has been assessed. We find that about half of the claimants, those not granted compensation, return to an earnings level comparable with their pre-whiplash earnings suggesting that these individuals do not have chronic WAD in the sense that their earnings capacity is reduced. The other half, those granted compensation, experience persistent reductions in earnings relative to the case where they had not been exposed to a whiplash, even when they have a strong financial incentive to not reduce earnings. This suggests that moderate injuries tend to be chronic, and that compensation-seeking behaviour is not the main explanation for this group. We find that claimants with chronic WADs used more health care in the year prior to the whiplash than claimants with non-chronic cases. This suggests that lower initial health capital increases the risk that a whiplash causes persistent WAD.     

Association between body mass index and recovery from whiplash injuries: a cohort study

It is hypothesized that excess weight is a risk factor for delayed recovery from neck pain, such as from whiplash injuries. However, the association between obesity and recovery from whiplash injury has not been studied. The authors examined the association between body mass index and time to recovery from whiplash injuries in a population-based cohort study of traffic injuries in Saskatchewan, Canada. The cohort included 4,395 individuals who made an insurance claim to Saskatchewan Government Insurance and were treated for whiplash injury between July 1, 1994, and December 31, 1995. Of those, 87.7% had recovered by November 1, 1997. No association was found between baseline body mass index and time to recovery. Compared with individuals with normal weight, those who were underweight (hazard rate ratio = 0.88, 95% confidence interval: 0.73, 1.06), overweight (hazard rate ratio = 1.01, 95% confidence interval: 0.94, 1.09), and obese (hazard rate ratio = 0.99, 95% confidence interval: 0.90, 1.08) had similar rates of recovery, even after adjustment for other factors. The results do not support the hypothesis that individuals who are overweight or obese have a worse prognosis for whiplash.     

Upper body quadrant pain in bus drivers

The aims of this study were to evaluate the prevalence of upper body quadrant pain among Israeli professional urban bus drivers and to evaluate the association between individual, ergonomic, and psychosocial risk factors and occurrence of neck pain. Three hundred and eighty-four male urban bus drivers were consecutively enrolled in the study. Data pertaining to work-related ergonomic and psychosocial stress factors were collected. The 12-month prevalence of neck pain was 21.2%, followed by shoulder: 14.7%, upper back: 8.3%, elbow: 3.0%, and wrist: 3.0% pain. Prevalence of neck pain was associated with uncomfortable seats (odds ratio; OR [95% confidence interval; CI]: 2.2 [1.2-4.3], back support (2.3 [1.2-4.2]), and steering wheel (2.2 [1.1-4.5]). Drivers with neck pain reported significantly higher prevalence of pain in the upper back (OR [95% CI]: 5.9 [2.7-12.9]), shoulders (8.1 [4.3-15.3]), and wrists (7.0 [2.0-21.8]) compared to drivers without neck pain. Work-related organizational stress factors were not associated with neck pain prevalence.     

Work environment and neck and shoulder pain: the influence of exposure time. Results from a population based case-control study

Objectives: To study associations between long term and short term exposure to different work environmental conditions and the incidence of neck or shoulder pain. The results were obtained as part of the MUSIC-Norrtälje study, which is a population based case-control study conducted in Sweden in 1993–7.

Methods: The cases were people from the study base who sought medical care or treatment for neck or shoulder pain. Information on physical and psychosocial conditions in the work environment, currently and 5 years ago, and lifestyle factors, was obtained by self administered questionnaires from 310 cases and 1277 randomly selected referents.

Results: Associations between both physical and psychosocial exposures in the work environment and seeking care for neck or shoulder pain were found. The risk patterns differed for the sexes, and risk ratios exceeding 1.5 were more often found among women than among men. Generally, subjects who had experienced a recent increase of exposure were more likely (relative risk (RR) 2.1–3.7) to seek care than those who had been exposed long term (RR 1.5–1.8). Among women, an increased amount of visual display terminal (VDT) work, work above shoulder level, and reduced opportunities to acquire new knowledge, and among men, an increased amount of seated work were associated with neck or shoulder pain. This might indicate short induction periods for neck or shoulder pain for these exposures. However, for repetitive work with the hands and hindrance at work among women, and possibly also local vibrations among men, the induction periods seem to be longer. Interactive effects between factors, both at work and in the family, were found, but only among women.

Conclusions: Associations between some exposures in the work environment and seeking care for neck or shoulder pain were found. The high RRs for short term exposure might indicate that for many factors the induction period for neck or shoulder pain is short.

     

Physical capacity in relation to low back, neck, or shoulder pain in a working population

Aims

To investigate the longitudinal relation between physical capacity (isokinetic lifting strength, static endurance of the back, neck, and shoulder muscles, and mobility of the spine) and low back, neck, and shoulder pain.

Methods

In this prospective cohort study, 1789 Dutch workers participated. At baseline, isokinetic lifting strength, static endurance of the back, neck, and shoulder muscles, and mobility of the spine were measured in the pain free workers, as well as potential confounders, including physical workload. Low back, neck, and shoulder pain were self‐reported annually at baseline and three times during follow up.

Results

After adjustment for confounders, Poisson generalised estimation equations showed an increased risk of low back pain among workers in the lowest sex specific tertile of performance in the static back endurance tests compared to workers in the reference category (RR = 1.42; 95% CI 1.19 to 1.71), but this was not found for isokinetic trunk lifting strength or mobility of the spine. An increased risk of neck pain was shown for workers with low performance in tests of isokinetic neck/shoulder lifting strength (RR = 1.31; 95% CI 1.03 to 1.67) and static neck endurance (RR = 1.22; 95% CI 1.00 to 1.49). Among workers in the lowest tertiles of isokinetic neck/shoulder lifting strength or endurance of the shoulder muscles, no increased risk of shoulder pain was found.

Conclusions

The findings of this study suggest that low back or neck endurance were independent predictors of low back or neck pain, respectively, and that low lifting neck/shoulder strength was an independent predictor of neck pain. No association was found between lifting trunk strength, or mobility of the spine and the risk of low back pain, nor between lifting neck/shoulder strength or endurance of the shoulder muscles and the risk of shoulder pain.     

Hypospadias in sons of women exposed to diethylstilbestrol in utero

BACKGROUND: Diethylstilbestrol (DES) is a synthetic estrogen that was widely prescribed to pregnant women before 1971. DES increases the risk of breast cancer in women who took the drug and the risk of reproductive tract abnormalities in their offspring. Dutch investigators have reported a 20-fold increase in risk of hypospadias among sons of women who were exposed to DES in utero. We assessed this relation in data from an ongoing study of DES-exposed persons. METHODS: Several U.S. cohorts of women with documented exposure in utero to DES have been followed by mailed questionnaires since the 1970s. Comparison subjects are unexposed women of the same ages. In 1997, participants were asked about congenital abnormalities in their children. We calculated prevalence odds ratios for the risk of hypospadias in sons of exposed mothers relative to sons of unexposed mothers using generalized estimating equations to adjust for multiple sons per mother and controlling for maternal age at the son's birth. RESULTS: We obtained data from 3916 exposed and 1746 unexposed women. These women reported a total of 13 liveborn sons with hypospadias (10 exposed, 3 unexposed). The prevalence odds ratio for risk of hypospadias among the exposed was 1.7 (95% confidence interval = 0.4-6.8). CONCLUSIONS: Our findings do not support a greatly increased risk of hypospadias among the sons of women exposed to DES in utero, as has been previously reported.     

Life events and the risk of low back and neck/shoulder pain of the kind people are seeking care for: results from the MUSIC-Norrtalje case-control study

OBJECTIVE: To expand the knowledge about the occurrence of life events, and how they affect the risk of low back and neck/shoulder pain. DESIGN: A population-based case-control study. SETTING: Men and women 20-59-years old, living in and not working outside the municipality of Norrt?lje, Sweden, from November 1993 to November 1997. PARTICIPANTS: Cases (n = 1,148) were defined as all subjects from the study base who sought healthcare for a new episode of low back and/or neck/shoulder pain by any of the care givers in the municipality. Controls (n = 1,700) were selected as a stratified random sample from the study base, considering sex and age. Study subjects were interviewed about life events and critical life changes. Critical life changes were defined as events that brought about a marked psychosocial change. Odds ratios (ORs) associated with different numbers of life events or critical life changes were calculated. RESULTS: Having experienced at least two life events during the preceding 5 years was associated with an increased risk of neck/shoulder pain (OR = 1.6, 95% CI 1.1 to 2.4). At least two critical life changes were associated with an increased risk of neck/shoulder pain (OR = 1.9, 95% CI 1.3 to 2.7). In general, no associations were observed in relation to risk of low back pain. CONCLUSION: Life events and critical life changes are of importance for the risk of neck/shoulder pain of the kind that people are seeking care for. The study provides useful information for clinical practice and for future aetiological research on neck/shoulder pain.     

Labor of freight-container tractor drivers and low-back pain. Characteristics of the low-back pain through clinical findings

In order to clarify the characteristics of the low-back pain which is prevalent among freight-container tractor drivers, a medical examination, composed of orthopedic tests and questions about health conditions, was carried out on 231 tractor drivers. Prevailing complaints were: dullness or stiffness of the shoulder (71%); dullness of the neck (69%); dullness of the low back (62%); low-back pain (42%); dullness of the lower limbs (39%) and dullness of the back (36%). The rates of complaints of dullness or pain of the neck, shoulder, upper limbs, back or lower limbs, and disturbance of daily activity were associated with the grade of low-back pain evaluated from the subjective symptoms. Orthopedic examination revealed fatigue signs of muscles i.e. tenderness of the body trunk and limbs, tenderness or percussion pain on the spinous processes, and poor results in some tests on muscle strength. These findings were seen more frequently in the group with subjective symptoms, but even among the group without symptoms, they were evident to some degree. These findings were considered to originate from the fact that the freight-container tractors had many ergonomic problems and the daily driving hours of many drivers were estimated to exceed the allowable vibration exposure time of the ISO.     

The association between neck pain intensity, physical functioning, depressive symptomatology and time-to-claim-closure after whiplash

Time-to-claim-closure is a common outcome in cohort studies of whiplash injuries. However, its relationship to health recovery is unknown. We investigated the association between neck pain, physical functioning, depressive symptomatology and time-to-claim-closure in a Saskatchewan cohort of 5398 whiplash claimants in 1994-1995. Participants were surveyed five times over 1 year. In 1995, the insurance system changed from tort to no-fault, eliminating compensation for pain and suffering. Under tort, a 10-point increase in pain reduced the claim-closure rate by 13-24% while a 10-point increase in physical functioning increased it by 17%. Depressive symptomatology reduced the claim-closure rate by 37%. Under no-fault, a 10-point increase in pain reduced the claim-closure rate by 18% while a 10-point increase in physical functioning increased it by 10-35%. The presence of depressive symptomatology reduced the claim-closure rate by 36%. The results suggests lower pain, better function and the absence of depressive symptoms are strongly associated with faster time-to-claim-closure and recovery after whiplash, independent of the insurance system.     

Outcome of the abduction external rotation test among manual and office workers

Reactions during the Abduction External Rotation (AER) test were studied among 71 platers and 70 assemblers exposed to vibratory tools and manual work and 45 unexposed white collar workers. The frequency of positive neurological reactions was 31% among the platers, 6% among the assemblers, and 16% among the white collar workers. Platers reported the highest fatigue rates in the shoulder regions during the test. A positive association was noted between a pathological AER test and current problems in the neck/scapula or shoulder/upper arm regions, day- or night-time numbness in the hands, tension neck, and carpal tunnel syndrome. Age, length of daily vibration exposure, and vibration acceleration level were also positively associated with a positive AER test outcome. The results indicate that the outcome of the AER test is sensitive to neck and shoulder disorders but also, to some extent, to the carpal tunnel syndrome.     

Mechanical and psychosocial factors predict new onset shoulder pain: a prospective cohort study of newly employed workers

Aim: To test the hypothesis that work related mechanical and psychosocial factors predict new onset shoulder pain in newly employed workers.

Methods: Two year prospective study of newly employed workers from 12 diverse occupational settings. At baseline, 1081 subjects provided information on work related mechanical and psychosocial risk factors, and current pain status.

Results: In all, 803 (74%) subjects were free from shoulder pain at baseline. Of those, 638 (79%) responded at 12 months and 476 (88%) at 24 months. New onset shoulder pain was reported by 93 (15%) and 73 (15%) subjects respectively. An increased risk of symptom onset was found in subjects reporting mechanical exposures involving heavy weights including lifting with one or two hands, carrying on one shoulder, lifting at or above shoulder level, and pushing or pulling. Working with hands above shoulder level was also predictive of new onset shoulder pain. Of the psychosocial factors examined, the strongest predictor was monotonous work. Those individuals with any other previous pain also had an increased risk of new onset shoulder pain at follow up. In multivariate analysis, lifting heavy weights with one or two hands, pushing or pulling heavy weights, working with hands above shoulder level, and monotonous work were independently associated with new onset shoulder pain.

Conclusions: This study supports the hypothesised relation between mechanical risk factors and shoulder pain. In general, work related psychosocial factors were modestly associated with new onset shoulder pain. However, monotonous work was a strong risk factor for new onset shoulder pain.

     

Work-related psychosocial and mechanical risk factors for neck/shoulder pain: a 3-year follow-up study of the general working population in Norway

Purpose

This study examines the impact of work-related psychosocial and mechanical exposure on the development of neck/shoulder pain in the general working population.

Methods

A randomly drawn cohort from the general population in Norway aged 18–66 was followed up for 3 years (n = 12,550, response rate = 67 %). Eligible respondents were in paid work during the reference week in 2006 and 2009, or temporarily absent from such work (n = 6,745). Four work-related psychosocial factors and six mechanical exposures were measured. Outcomes of interest were moderate or severe neck/shoulder pain at follow-up adjusted for baseline neck/shoulder pain.

Results

In total, 16.9 % (1,138 individuals) reported neck/shoulder pain during the last month at follow-up. Work related psychosocial predictors of neck/shoulder pain were high job demands (highest OR 1.41, 95 % CI 1.11–1.78) and low levels of supportive leadership (highest OR 1.66, 95 % CI 1.08–2.54). Mechanical factors were neck flexion (highest OR 1.77, 95 % CI 1.31–2.39) and lifting in awkward postures (highest OR 1.81, 95 % CI 1.21–2.71). The estimated population risk attributable to these factors was about 23 %. The relative risk for neck/shoulder pain associated with psychosocial exposure was slightly influenced by adjustment for physical risk factors, and vice versa. There was no substantial confounding related to age, gender, education, occupation or psychological distress.

Conclusions

Highly demanding jobs, neck flexion and awkward lifting appear as the most important predictors of neck/shoulder pain.     

Whiplash, chronic neck pain, and zygapophyseal joint disorders. A selective review

Recent research on whiplash injury has challenged the long-held view of what causes chronic neck pain in car accident victims. Although it was previously thought to result from residual scarring of muscles and ligaments, such pain is now understood to be caused by zygapophyseal-joint damage, which produces no objective findings on radiologic testing and often none on physical examination. Chronic pain from a whiplash injury can be reliably diagnosed and effectively treated in most patients by z-joint testing and radiofrequency blocks.     

High incidence and recurrence of shoulder and neck pain in nursing home employees was demonstrated during a 2-year follow-up

OBJECTIVE: This study describes the course of shoulder and neck complaints in a working population over time. STUDY DESIGN AND SETTING: Questionnaires were administered on neck and shoulder complaints over 3 consecutive years. RESULTS: We observed 12-month incidence rates for neck and shoulder complaints of 16% to 18%, 12-month prevalence rates roughly twice as high, and 12-month recurrence rates approximately twice the prevalence rates. Each year, medical care was sought by 21% to 38% of the subjects with neck or shoulder pain, and 13% to 21% were absent from work. Although at the population level the occurrence of neck and shoulder complaints remained constant, the course of complaints within individuals demonstrated a strong episodic nature of neck and shoulder pain. Results from this study suggest that neck and shoulder complaints for most subjects run a recurrent course characterized by a strong variation in occurrence and a self-limiting course. CONCLUSION: These findings suggest that clinical trials should have a sufficiently long follow-up period to demonstrate sustainability of the therapeutic results.     

Seeking care for neck/shoulder pain: a prospective study of work-related risk factors in a healthy population

This study estimated the 5-year cumulative incidence of neck/shoulder pain and identified work-related risk factors leading subjects to seek care for this problem. Four to six years after the case-referent MUSIC-Norrt?lje Study, a postal questionnaire was sent to the referents of this study, and 81% responded. At baseline, 516 men and 697 women were assessed as to their work-related exposures. The 4- to 6-year cumulative incidence for seeking care for neck/shoulder pain was 29% for women and 18% for men. For men, moderately increased risks were found for manual handling, night work/shift work, hindrances at work, and solitary work. For men, the risk increased with an increasing number of risk indicators. No work-related risk factors were found for women, highlighting the difficulty of identifying risk factors in a general population.     

Shoulder disorders and postural stress in automobile assembly work

OBJECTIVES: A case-referent study was conducted in an automobile assembly plant to evaluate the risk of shoulder disorders associated with nonneutral postures. METHODS: The cases were workers who reported shoulder pain to the plant clinic during a 10-month period and met symptom criteria (pain frequency or duration in the past year) in an interview; more than one-half also had positive findings in a physical examination. The referents were randomly selected workers who were free of shoulder disorders according to the clinic records, the interview, and the physical examination. For each of the 79 cases and 124 referents, 1 job was analyzed for postural and biomechanical demands by an analyst blinded to the case-referent status. RESULTS: Forty-one percent of the subjects flexed or abducted the right arm "severely" (above 90 degrees) during the job cycle, and 35% did so with the left arm. The peak torques at the shoulder were rather low. Shoulder disorders were associated with severe flexion or abduction of the left [odds ratio (OR) 3.2, 95% confidence interval (95% CI) 1.5-6.5] and the right (OR 2.3, 95% CI 1.2-4.8) shoulder. The risk increased as the proportion of the work cycle exposed increased. The relationships were similar for the cases with and without physical findings. Use of hand-held tools increased the risk and also modified the association with postural stress, although the joint exposure distributions limited full analysis of this finding. CONCLUSIONS: The findings support the conclusion that severe shoulder flexion or abduction, especially for 10% or more of the work cycle, is predictive of chronic or recurrent shoulder disorders.     

Occupational cervicobrachial disorder (OCD) of nursery school teachers based on subjective symptoms related to OCD

To clarify the association of occupational cervicobrachial disorder (OCD), with labor conditions, and personal situation, a questionnaire study was conducted among nursery school teachers. The questionnaire was composed of subjective symptoms related to OCD (neck, shoulder, back and arm stiffness/pain), labor conditions, and whether or not the teacher had a child of her own under the age of two. Data of 793 subjects were analyzed. The results were as follows: The mean age and working period of 793 subjects were 27.6 (+/- 4.9) and 5.5 (+/- 3.2) years, respectively. Of them, 38.5% complained of right shoulder stiffness every day during the prior month, 26.5% neck stiffness, 18.8% arm stiffness, 9.6% back pain, 7.8% shoulder pain and 3.9% arm pain. The complaint rates on the left side were similar to those on the right side. The complaint rates of these subjective symptoms increased with the duration of the working period. The complaint rates of shoulder, neck and arm stiffness increased earlier than those of back stiffness, shoulder or arm pain. The complaint rates of these symptoms were highest among teachers in charge of children less than one-year-old and those in charge of four-year olds. Teachers in charge of three-year-old children had the lowest complaint rates. Subjects complaining of neck, shoulder and arm stiffness on every day worked under less favorable conditions than those without such complaints. When subjects having no children of their own under the age of two were matched in their ages and length of work history with those who have such children, the complaint rates of the two groups did not differ statistically for any of the subjective symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cellular phones and traffic accidents

Cellular phone use in motor vehicles is becoming an increasing world-wide phenomenon. Using data obtained from traffic accidents reported between 1992 and 1995 in the state of Oklahoma, USA, this study examined statistical rate-ratios of accident characteristics between drivers with or without cellular phones. Rates were calculated between cellular phone involvement and reported accident causes, types of collision, driver actions immediately prior to the accident, location of the accident, the extent of fatalities, and age and gender of drivers. Results indicated a significant increased rate among drivers with cellular phones for inattention, unsafe speed, driving on wrong side of road, striking a fixed object, overturning their vehicle, swerving prior to the accident, and running off the roadway. People with phones stood an increased risk of being killed in an accident over persons without phones. Males with phones had a significantly higher rate than females for many of accident characteristics mentioned above. Rate-ratios of some accident characteristics and fatalities increased as age increased, with the exception of drivers under age 20 yrs, who had the highest fatality rate. Limitations of the study and possible prevention alternatives are discussed.